Tunable THz Angular/Frequency Filters in the Modified Kretschmann–Raether Configuration With the Insertion of Single Layer Graphene

Tunable terahertz (THz) angular/frequency filters in the modified Kretschmann-Raether configuration with the insertion of single-layer graphene have been numerically demonstrated. Due to the excitation of the transverse magnetic (TM) polarized surface plasmons at the interface of two dielectrics with the insertion of the graphene sheet, the transmission resonance occurs at some range incident angles and frequencies in the THz frequency range, which can be adopted for designing the angular/frequency filters. It is shown that the resonant angle and the resonant wavelength can be tuned by varying the Fermi energy of the graphene sheets via electrostatic biasing. Moreover, we show that the resonant behaviors can be engineered by changing the gap thickness or the incident angle.